There was a proposal, called TESLA for a 500GeV linear collider, combined with an X-Ray FEL at DESY. They built a far ultra-violet FEL as a technology demonstrator for this.
The recent announcement is that the accelerator technology that had also been developed for TESLA, using superconducting resonant cavities to support very high intensity microwave standing waves that actually accelerate the electrons has been chosen from among four candidates as the acclerator technology for the ILC project. That may or may not be buolt at DESY, and will not, as far as I know, incorporate an X-ray FEL.
Of course the cost of this kind of networking technology does eat up quite a lot of the cheapness factor. In many clusters the interconnect costs more than, sometimes several times more than, the processors,memory, etc.
Say, how big is this slab, anyhow? And where did anyone get the idea it would make a 300 foot wave?
It's "the size of the Isle of Wight" (about 20 miles by 15) and they go tthe wave height from theoretical models and scaled-down tank experiments. When the slab goes it displaces a lot of water, and the only place that can go, initially,
is into the wave.
Actually, if you could set off a bunch of other Tsunami so phased your major cities were all in the spots where the interference cancelled the wave, this might be kind of cool. Of course the "less-valuable" areas between the cities, would get two or three times the damage, but this could still be a win. I'm not sure we have enough explosives (and yes, I'm counting nukes) to create waves on the necessary scale, however.
There are so many misconceptions among the various responses to this post that it's a little hard to know where to start.
1. A solar sail powered by sunlight (not by the solar wind) is only useful within the (inner) solar system, maybe as far out as Jupiter or so. Within that area, it is pretty useful if you're not in too much of a hurry. You can use the Sun's gravity, and angle the sail to move around the inner system fairly freely, if slowly. I've seen plans for a solar sailing mission to Mercury that looked very promising. Lots of light there, and getting there any other way is hard work. Also the sail makes a dandy sunshade.
2. For interstellar missions you need a light beam to sustain the acceleration long enough. You then (unless you just want to do a fly-through, need to find a way of stopping. Science Fiction offers three options, none ideal:
a) dump all excess mass and dive close to the target star. Hope to stop before you burn -- "The Mote in God's Eye" approach.
b) split off part of the sail as a reflector which flies on ahead, bouncing the beam back onto the main part of the sail, which brakes the ship -- "The Flight of the Dragonfly" approach. Stability is a problem, even with active controls.
c) charge the ship to a high voltage, let the galactic magnetic field spin you round and enter the target system from behind. Use your original beam to decellerate -- galactic magnetic fields are pretty fickle and this could add a lot of time to the mission. (also mentioned in "The Mote in God's Eye"
3. There are other kinds of sail. A magnet (presumably in the form of a large loop of (super-)conductor will deflect charged particles, stealing momentum from them. This "magsail" really does sail on the solar wind. The attraction is need be little more than a wire loop, so it can be really big. A beam-riding version would need a beam of charged particles. This is probably sent as a beam of neutral particles (anything from hydrogen atoms to missiles) and then blasted to ions by a laser cannon on the ship at the last moment -- charged beams spread.
Unfortunately, it turns out that the interstellar medium is much thinner, in most places and in particular around the Sun, than Bussard thought. Even if you could somehow persuade protons to fuse in the few nanoseconds while they are passing through your ship at nearly the speed of light (and on average it takes about 15 billion years for any given proton to fuse in the core of the Sun), there just aren't many of them around here.
A beamrider of some kind (leave the engines at home and ship momentum up to the spacecraft in some convenient form) or an antimatter rocket are looking like the best ideas at present.
The retro burn wasn't to mitigate collision danger in the rings, it was to get inbto orbit around Saturn (instead of flying off out of the solar system). The dynamics mean that you get the most benefit from the least fuel by burning it as close to Saturn as possible. Given the difficulty of getting fuel that far, this must be the dominant consideration in the planning of the manouver. Having decided how long they needed to burn and where, then they could consider other issues.
Nothing very remarkable. It was launched on a big chemical booster with various upper stages. It then did the usual gravitational dance passing by Venus, Earth (twice) and Jupiter before getting to Saturn. It has a few small rocket engines on board, a biggish one that it just fired for 96 minutes to get into orbit around Saturn, and a bunch of tiny ones for attitude control and fine steering. From here on, though it will basically use the gravity of Saturn's various moons to "bounce" around and visit them.
It does have a nuclear electrical source on board but that is not used for propulsion.
Even between flares, I don't think being in the sun is too healthy in the long term. Does anyone have hard data?
I really don't think cold is a problem. If you make the base reasonably shiny it won't radiate much -- getting rid of heat is likely to be a bigger problem than keeping warm.
There is a problem with temperatures, but it doesn't work quite the same way on the Moon as you seem to think. There is (basically) no atmosphere, so there is no "current air temperature" as there is on Earth. The rock surface varies from very hot after being in sunlight for a while to very cold after being in shadow for a while, but the rock is a very poor conductor, and it is not hard to insulate the base from the rock it's standing on (or rolling over) or simply to heat or cool the small amount of immediately adjacent rock and use the rock itself as insulator.
The main issue is radiation. If you are in sunlight, you get intense radiant heat from the sun, which, depending on what colour you are, you may or may not absorb. If you're not, and can see open space, then you radiate heat to it, again depending on what colour you are. Finally, you have to get rid of the heat generated by your people and machinery, which can be a problem, especially if you are underground.
These are all issues that need attention, but it should not actually be too hard to keep all, or most of the materials that make up the base at more or less whatever temperature you want. To a large extent this can be done with surface coating -- shiny at optical wavelengths to reflect sunlight, darker at IR wavelengths to radiate internal heat, etc. Some active heat pumping might also be needed.
The moon rotates every 29 plus days, call it 700 hours.
The diameter of the moon is about 2162 miles, so the circumference is about 6800 miles. So at less than 10 mph, even at the equator, you can keep the entire moon between you and solat radiation.
Not realistic at the equator, but rather fun.
Nearer the poles though, this could be entirely feasible. Use the mobile base to simply avoid daylight.
Firstly the c is redundant. In proper post-Einstein physics, distance and time are the same, so a speed is simply a pure number, so:
My car tops out at about 0.000000231 (or 2.31 x 10^-7)
Now for distance, or time, we need to fix a unit of distance OR time. The most obvious fundamental unit of distance is the Planck length
It can travel about 3 x 10^38 Planck lengths on a tank of gas [ remark -- your car may need maintenance, that's not very far]
Power is energy (aka mass) per unit time, so again, we appeal to Planck and find that your car produces about 4 * 10^-48 Planck masses per Planck time.
Now we've got rid of all the silly arbitrary unit standards and defined everything in terms of the fundamental properties of the universe. Most physical constants are 1 in this model, which is a handy side benefit.
Of course there is some contention over the pint (and consequently the gallon). An imperial pint is 20 fluid ounces (a little over half a litre). A US pint is 16 fluid ounces (under half a litre), leading to the factually incorrect US maxim "a pint's a pound the world around". I think there is a small difference in the fluid ounce as well.
The evidence for dark matter is its gravitational effect on relatively small things like galaxies, which can be examined quite accurately by looking at the mov ements of stars, the distribution of dust and gas and so on. They all confirm that there is a lot of stuff in galaxies (and not in the space between) that we can't see, and give us a pretty good idea about how it is distributed within the galaxies and so on. It seems pretty clear that this really is matter, subject to gravity in the normal way, and fairly unaffected by things like magnetic fields. The only real question is WHAT KIND OF MATTER it is. People have suggested everything from "failed stars" not quite big enough to ignite to various kinds of new, heavy, stable and not very interactive particles.
Dark energy is much more mysterious, and can be viewed as just a name for certain basic properties of the Universe changing with time, or not working quite the way we thought. It is essentially just a name for whatever it is that explains why the expansion of the universe seems to be speeding up, rather than slowing down as expected.
No. D+T is easier, but produces neutrons. The neutrons need to be absorbed into a Lithium blanket to breed more T. This does however also involve spraying the inner parts of the reactor structure with neutrons, producing some medium-level radioactive waste (although far less per GW year than fission.
D+He3 produces next to no neutrons, but there is no decent source of He3.
I was told recently that D+D can be "discouraged" from producing neutrons by doing something clever with magnetic fields and nuclear spins.
I am describing how the concept of "shape" is DEFINED intrinsically to a space. I used a 2D space (the surface of the Earth) as an example, because it's easier to think about. In 3D you consider tetrahedra, and measure solid angles, and I don't actually know the details.
That's how you DEFINE the shape of space. Actually measuring it that way is too hard -- anywhere except close to a big mass it is flat to within the limits of this kind of measurement, and when you do get results they tell you about little local bumps like the Earth, the Sun and the Galaxy, not about the big picture.
So, we measure the overall average shape of space indirectly -- we look, for instance, for variations in the microwave background which tell us about the size and shape of space a very long time ago (when the universe was smaller) or make rather subtle arguments based on th edistribution and brightness of things like supernovae.
As for how you measure angles in 2D -- you measure distance along an arc of a circle.
You can determine the "shape" of a piece of space from inside it. Let me drop down one dimension and consider the shapes of surfaces. We all know that the angles at the corners of a triangle add up to 180 degreed. This, however is only actually true, when you draw your triangle on a truly flat surface. On a curved surface such as that of the Earth, the angles will add up to MORE THAN 180 degrees. Consider, for example a triangle with one vertex at the N pole, and two 90 degrees apart on the equator, with its edges made of great circles (the appropriate analogue of a straight line). All THREE angles of this triangle are right angles.
In fact, on a sphere of radius R, the sum of the angles exceeds 180 degrees by 180/pi * A/r^2, where A is the area of the triangle.
On a saddle-shaped surface, the angles of a triangle are always LESS THAN 180 degrees in a similar way.
Building on these ideas, you can define a precise notion of the shape of a surface entirely from INSIDE the surface, and extend it up to three dimensions (or more) dimensions. This is what the cosmologists are talking about when they talk about the "shape" of the universe.
The article says that they are selling this as a technology for mastering Blu-ray or equivalent next-generation DVD products. These are just starting to appear with capcities around 20-50 GB per side per layer. They are read (and sometimes (re)written) with blue light, but again, the article says, to make high quality masters they are using UV lasers, which are expensive and complicated. The e-beam is being sold as a higher quality, and cheaper way to make these masters.
This is pretty amazing if they get this down to consumer price.
Their is no suggestion that this is a device aimed at the consumer market. They are selling this as a way to make the master disks used to press consumer disks.
All fully accepted. The factor of 10 in the ignition temperature is far from trivial though, and I did say "in the medium term". In the longer term, ignoring the possibility of "magic" like cold fusion, or extracting energy from the quantum vacuum then an aneutronic fusion process seems like a good option. It's that or use the really big gravitationally confined proton-proton fusion reactor that's sitting 93 million miles away.
Do you have a reference for the business with D-D reactions and magnetic fields.
Break even and ignition are two separate things. Break even means that the total fusion energy produced exceeds the energy put into heating the ingredients. I think JET achieved break even in a tokamak, and it's even easier in laser fusion.
Ignition means that the energy being produced by fusion and re-absorbed in the plasma is keeping it hot enough to keep on fusing with no external energy inputs until some other factor (like running out of fuel or the plasma blowing itself apart) intervenes. This has only been acheived in bombs.
As an analogy consider trying to light a recalcitrant campfire. Break even is when the total energy produced by your buring wood before it sputters out exceeds the energy put in by the match. Ignition is when it keeps burning on its own.
Think of it as a long-term investment for the human race, that over the course of human history will pay itself off millions of times over. Clean energy (only byproducts = water & heat, no radioactive byproducts) from the most abundant source in the universe (hydrogen) with significantly less risk than fission power (or arguably even fossil fuels).
Fusion power generation, as currently being developed is nothing like this. It's still a sensible investment for the next few centuries and as a step to better things, but it's not the panacea you suggest and you harm the credibility of science and technology by claiming it is.
Likely 21st century fusion power plants will burn tritium and deuterium. While both are isotopes of hydrogen and deuterium is acceptably common in the universe (1 in 10000 or so atoms if I recall correctly) we are not burning hydrogen. Tritium is radioactive with a 12 year half-life, so is basically not found in the universe except where it is being formed (in stars mostly). To make commercial quantities of it, you irradiate lithium 6 with neutrons producing helium and tritium. Lithium is reasonably common on Earth, but not super-abundant. The costs of extracting and purifying lithium, and in particular lithium 6 are not negligible, although we are unlikely to run out for a while.
So, effective fuel is lithium and deuterium. Both are reasonably plentiful, but neither is cost-free.
Now the tricky bit. The deuterium-tritium reaction produces a helium nucleus (alpha-particle) which is no problem and a neutron. We need a decent proportion of those neutrons to breed more tritium, but inevitably, some of them will end up hitting things other than the lithium target. When they do, they tend to make what they hit radioactive. Thus, once your reactor has been running for a few years, all of the inner structure, the lithium tanks and so on, are medium-level radioactive waste. The neutron irradiation also weakens these structures, so they need periodic replacement. Gigawatt for Gigawatt, it's a lot less radioactive waste than a fission reactor produces (and no plutonium to manage), but its not nothing, and the cost of the equipment and expertise to manage this periodic replacement with acceptable staff safety and so on is also not nothing. Water, by the way, is not a byproduct of fusion reactors.
The final issue is safety. Here the big win is that there are no realistic disaster scenarios on the scale of a fission reactor melt-down or someone using reactor-produced plutonium to make a fission bomb. There are all the hazards common to fossil fuels and fission associated simply with running a large industrial plant -- things falling on people, leaking chemicals, etc. A tritium leak is still a real hazard, and a molten lithium leak or fire would be pretty unpleasant, and the medium-level waster would need to be managed, but it is a lot better than fission.
So, not a panacea, but a likely move forward, and I don't think we do any good by describing it as a panacea and rasing false expectations.
Slashdot Mirror
There was a proposal, called TESLA for a 500GeV linear collider, combined with an X-Ray FEL at DESY. They built a far ultra-violet FEL as a technology demonstrator for this.
The recent announcement is that the accelerator technology that had also been developed for TESLA, using superconducting resonant cavities to support very high intensity microwave standing waves that actually accelerate the electrons has been chosen from among four candidates as the acclerator technology for the ILC project. That may or may not be buolt at DESY, and will not, as far as I know, incorporate an X-ray FEL.
Of course the cost of this kind of networking technology does eat up quite a lot of the cheapness factor. In many clusters the interconnect costs more than, sometimes several times more than, the processors,memory, etc.
Actually, if you could set off a bunch of other Tsunami so phased your major
cities were all in the spots where the interference cancelled the wave, this might be kind of cool. Of course the "less-valuable" areas between the cities, would get two or three times the damage, but this could still be a win. I'm not sure we have enough explosives (and yes, I'm counting nukes) to create waves on the necessary scale, however.
There are so many misconceptions among the various responses to this post that it's a little hard to know where to start.
1. A solar sail powered by sunlight (not by the solar wind) is only useful within the (inner) solar system, maybe as far out as Jupiter or so. Within that area, it is pretty useful if you're not in too much of a hurry. You can use the Sun's gravity, and angle the sail to move around the inner system fairly freely, if slowly. I've seen plans for a solar sailing mission to Mercury that looked very promising. Lots of light there, and getting there any other way is hard work. Also the sail makes a dandy sunshade.
2. For interstellar missions you need a light beam to sustain the acceleration long enough. You then (unless you just want to do a fly-through, need to find a way of stopping. Science Fiction offers three options, none ideal:
a) dump all excess mass and dive close to the target star. Hope to stop before you burn -- "The Mote in God's Eye" approach.
b) split off part of the sail as a reflector which flies on ahead, bouncing the beam back onto the main part of the sail, which brakes the ship -- "The Flight of the Dragonfly" approach. Stability is a problem, even with active controls.
c) charge the ship to a high voltage, let the galactic magnetic field spin you round and enter the target system from behind. Use your original beam to
decellerate -- galactic magnetic fields are pretty fickle and this could add a lot of time to the mission. (also mentioned in "The Mote in God's Eye"
3. There are other kinds of sail. A magnet (presumably in the form of a large loop of (super-)conductor will deflect charged particles, stealing momentum from them. This "magsail" really does sail on the solar wind. The attraction is need be little more than a wire loop, so it can be really big. A beam-riding version would need a beam of charged particles. This is probably sent as a beam of neutral particles (anything from hydrogen atoms to missiles) and then blasted to ions by a laser cannon on the ship at the last moment -- charged beams spread.
Unfortunately, it turns out that the interstellar medium is much thinner, in most places and in particular around the Sun, than Bussard thought. Even if you could somehow persuade protons to fuse in the few nanoseconds while they are passing through your ship at nearly the speed of light (and on average it takes about 15 billion years for any given proton to fuse in the core of the Sun), there just aren't many of them around here.
A beamrider of some kind (leave the engines at home and ship momentum up to the spacecraft in some convenient form) or an antimatter rocket are looking like the best ideas at present.
Steve
The retro burn wasn't to mitigate collision danger in the rings, it was to get inbto orbit around Saturn (instead of flying off out of the solar system). The dynamics mean that you get the most benefit from the least fuel by burning it as close to Saturn as possible. Given the difficulty of getting fuel that far, this must be the dominant consideration in the planning of the manouver. Having decided how long they needed to burn and where, then they could consider other issues.
Nothing very remarkable. It was launched on a big chemical booster with various upper stages. It then did the usual gravitational dance passing by Venus, Earth (twice) and Jupiter before getting to Saturn. It has a few small rocket engines on board, a biggish one that it just fired for 96 minutes to get into orbit around Saturn, and a bunch of tiny ones for attitude control and fine steering. From here on, though it will basically use the gravity of Saturn's various moons to "bounce" around and visit them.
It does have a nuclear electrical source on board but that is not used for propulsion.
Even between flares, I don't think being in the sun is too healthy in the long term. Does anyone have hard data?
I really don't think cold is a problem. If you make the base reasonably shiny it won't radiate much -- getting rid of heat is likely to be a bigger problem than keeping warm.
There is a problem with temperatures, but it doesn't work quite the same way on the Moon as you seem to think. There is (basically) no atmosphere, so there is no "current air temperature" as there is on Earth. The rock surface varies from very hot after being in sunlight for a while to very cold after being in shadow for a while, but the rock is a very poor conductor, and it is not hard to insulate the base from the rock it's standing on (or rolling over) or simply to heat or cool the small amount of immediately adjacent rock and use the rock itself as insulator.
The main issue is radiation. If you are in sunlight, you get intense radiant heat from the sun, which, depending on what colour you are, you may or may not absorb. If you're not, and can see open space, then you radiate heat to it, again depending on what colour you are. Finally, you have to get rid of the heat generated by your people and machinery, which can be a problem, especially if you are underground.
These are all issues that need attention, but it should not actually be too hard to keep all, or most of the materials that make up the base at more or less whatever temperature you want. To a large extent this can be done with surface coating -- shiny at optical wavelengths to reflect sunlight, darker at IR wavelengths to radiate internal heat, etc. Some active heat pumping might also be needed.
The moon rotates every 29 plus days, call it 700 hours.
The diameter of the moon is about 2162 miles, so the circumference is about 6800 miles. So at less than 10 mph, even at the equator, you can keep the entire moon between you and solat radiation.
Not realistic at the equator, but rather fun.
Nearer the poles though, this could be entirely feasible. Use the mobile base to simply avoid daylight.
Rules out solar power, of course.
Steve
No, no no!
Firstly the c is redundant. In proper post-Einstein physics, distance and time are the same, so a speed is simply a pure number, so:
My car tops out at about 0.000000231 (or 2.31 x 10^-7)
Now for distance, or time, we need to fix a unit of distance OR time. The most obvious fundamental unit of distance is the Planck length
It can travel about 3 x 10^38 Planck lengths on a tank of gas [ remark -- your car may need maintenance, that's not very far]
Power is energy (aka mass) per unit time, so again, we appeal to Planck and find that your car produces about 4 * 10^-48 Planck masses per Planck time.
Now we've got rid of all the silly arbitrary unit standards and defined everything in terms of the fundamental properties of the universe. Most physical constants are 1 in this model, which is a handy side benefit.
Of course there is some contention over the pint (and consequently the gallon).
An imperial pint is 20 fluid ounces (a little over half a litre). A US pint is 16 fluid ounces (under half a litre), leading to the factually incorrect US maxim "a pint's a pound the world around". I think there is a small difference in the fluid ounce as well.
Steve
PS 1 stone is 14 pounds.
You're confusing dark matter with dark energy.
The evidence for dark matter is its gravitational effect on relatively small things like galaxies, which can be examined quite accurately by looking at the mov ements of stars, the distribution of dust and gas and so on. They all confirm that there is a lot of stuff in galaxies (and not in the space between) that we can't see, and give us a pretty good idea about how it is distributed within the galaxies and so on. It seems pretty clear that this really is matter, subject to gravity in the normal way, and fairly unaffected by things like magnetic fields. The only real question is WHAT KIND OF MATTER it is. People have suggested everything from "failed stars" not quite big enough to ignite to various kinds of new, heavy, stable and not very interactive particles.
Dark energy is much more mysterious, and can be viewed as just a name for certain basic properties of the Universe changing with time, or not working quite the way we thought. It is essentially just a name for whatever it is that explains why the expansion of the universe seems to be speeding up, rather than slowing down as expected.
No. D+T is easier, but produces neutrons. The neutrons need to be absorbed into a Lithium blanket to breed more T. This does however also involve spraying the inner parts of the reactor structure with neutrons, producing some medium-level radioactive waste (although far less per GW year than fission.
D+He3 produces next to no neutrons, but there is no decent source of He3.
I was told recently that D+D can be "discouraged" from producing neutrons by doing
something clever with magnetic fields and nuclear spins.
I am describing how the concept of "shape" is DEFINED intrinsically to a space. I used a 2D space (the surface of the Earth) as an example, because it's easier to think about. In 3D you consider tetrahedra, and measure solid angles, and I don't actually know the details.
That's how you DEFINE the shape of space. Actually measuring it that way is too hard -- anywhere except close to a big mass it is flat to within the limits of this kind of measurement, and when you do get results they tell you about little local bumps like the Earth, the Sun and the Galaxy, not about the big picture.
So, we measure the overall average shape of space indirectly -- we look, for instance, for variations in the microwave background which tell us about the size and shape of space a very long time ago (when the universe was smaller) or make rather subtle arguments based on th edistribution and brightness of things like supernovae.
As for how you measure angles in 2D -- you measure distance along an arc of a circle.
You can determine the "shape" of a piece of space from inside it. Let me drop down one dimension and consider the shapes of surfaces. We all know that the angles at the corners of a triangle add up to 180 degreed. This, however is only actually true, when you draw your triangle on a truly flat surface. On a curved surface such as that of the Earth, the angles will add up to MORE THAN 180 degrees. Consider, for example a triangle with one vertex at the N pole, and two 90 degrees apart on the equator, with its edges made of great circles (the appropriate analogue of a straight line). All THREE angles of this triangle are right angles.
In fact, on a sphere of radius R, the sum of the angles exceeds 180 degrees by 180/pi * A/r^2, where A is the area of the triangle.
On a saddle-shaped surface, the angles of a triangle are always LESS THAN 180 degrees in a similar way.
Building on these ideas, you can define a precise notion of the shape of a surface entirely from INSIDE the surface, and extend it up to three dimensions (or more) dimensions. This is what the cosmologists are talking about when they talk about the "shape" of the universe.
Sorry about the spelling error.
The article says that they are selling this as a technology for mastering
Blu-ray or equivalent next-generation DVD products. These are just starting to appear with capcities around 20-50 GB per side per layer. They are read (and sometimes (re)written) with blue light, but again, the article says, to make high quality masters they are using UV lasers, which are expensive and complicated. The e-beam is being sold as a higher quality, and cheaper way to make these masters.
Their is no suggestion that this is a device aimed at the consumer market. They are selling this as a way to make the master disks used to press consumer disks.
Thanks. That's helpful.
All fully accepted. The factor of 10 in the ignition temperature is far from trivial though, and I did say "in the medium term". In the longer term, ignoring the possibility of "magic" like cold fusion, or extracting energy from the quantum vacuum then an aneutronic fusion process seems like a good option. It's that or use the really big gravitationally confined proton-proton fusion reactor that's sitting 93 million miles away.
Do you have a reference for the business with D-D reactions and magnetic fields.
Steve
Break even and ignition are two separate things. Break even means that the total fusion energy produced exceeds the energy put into heating the ingredients. I think JET achieved break even in a tokamak, and it's even easier in laser fusion.
Ignition means that the energy being produced by fusion and re-absorbed in the plasma is keeping it hot enough to keep on fusing with no external energy inputs until some other factor (like running out of fuel or the plasma blowing itself apart) intervenes. This has only been acheived in bombs.
As an analogy consider trying to light a recalcitrant campfire. Break even is when the total energy produced by your buring wood before it sputters out exceeds the energy put in by the match. Ignition is when it keeps burning on its own.
Fusion power generation, as currently being developed is nothing like this. It's still a sensible investment for the next few centuries and as a step to better things, but it's not the panacea you suggest and you harm the credibility of science and technology by claiming it is.
Likely 21st century fusion power plants will burn tritium and deuterium. While both are isotopes of hydrogen and deuterium is acceptably common in the universe (1 in 10000 or so atoms if I recall correctly) we are not burning hydrogen. Tritium is radioactive with a 12 year half-life, so is basically not found in the universe except where it is being formed (in stars mostly). To make commercial quantities of it, you irradiate lithium 6 with neutrons producing helium and tritium. Lithium is reasonably common on Earth, but not super-abundant. The costs of extracting and purifying lithium, and in particular lithium 6 are not negligible, although we are unlikely to run out for a while.
So, effective fuel is lithium and deuterium. Both are reasonably plentiful, but neither is cost-free.
Now the tricky bit. The deuterium-tritium reaction produces a helium nucleus (alpha-particle) which is no problem and a neutron. We need a decent proportion of those neutrons to breed more tritium, but inevitably, some of them will end up hitting things other than the lithium target. When they do, they tend to make what they hit radioactive. Thus, once your reactor has been running for a few years, all of the inner structure, the lithium tanks and so on, are medium-level radioactive waste. The neutron irradiation also weakens these structures, so they need periodic replacement. Gigawatt for Gigawatt, it's a lot less radioactive waste than a fission reactor produces (and no plutonium to manage), but its not nothing, and the cost of the equipment and expertise to manage this periodic replacement with acceptable staff safety and so on is also not nothing.
Water, by the way, is not a byproduct of fusion reactors.
The final issue is safety. Here the big win is that there are no realistic disaster scenarios on the scale of a fission reactor melt-down or someone using reactor-produced plutonium to make a fission bomb. There are all the hazards common to fossil fuels and fission associated simply with running a large industrial plant -- things falling on people, leaking chemicals, etc. A tritium leak is still a real hazard, and a molten lithium leak or fire would be pretty unpleasant, and the medium-level waster would need to be managed, but it is a lot better than fission.
So, not a panacea, but a likely move forward, and I don't think we do any good by describing it as a panacea and rasing false expectations.
There's a "Best of Not the Nine O'Clock News" video released.